“If you could bottle all of these effects and put it in a pill, would we be in a different place now?”
That’s the question posed by Laura Baker, associate professor of Geriatric Medicine, Neurology and Public Health Sciences at Wake Forest School of Medicine. She was speaking at the Alzheimer’s Association International Conference in July.
Prof. Baker was describing something that’s available to everyone, is free of charge and is already known to reduce the risk of heart disease, stroke, diabetes and some forms of cancer.
She explained that few top quality studies have been conducted to see if it can reduce dementia risk. The audience listened attentively, but then sat up and took note as she presented some dramatic findings from her new study.
Here’s what got their attention – and mine. . .
Professor Baker demonstrated that not only can dementia be stopped in its tracks, it can even be reversed by exercise.
Exercise Reduces The Risk of Alzheimer’s by Nearly 50%
While it’s true that gold-standard studies are limited, nevertheless, 11 trials involving middle aged people over time showed that regular exercise can reduce the risk of dementia by nearly a third and the risk of Alzheimer’s by almost half.
Over a shorter period of a month or so, 29 trials found that regular aerobic exercise like walking, running, cycling and swimming led to better memory, attention and processing speed.
Even among people over 60, 26 studies show better cognitive performance in those who keep physically active.
For her own test of the concept, Prof. Baker enrolled patients aged 55 to 89 with mild cognitive impairment, a condition that often leads to Alzheimer’s.
One group engaged in 45 minutes of aerobic exercise in a gym four times a week using a stationary exercise machine, bike or treadmill. The aim was to reach about 70% of maximum heart rate.
A second group just performed some gentle stretching exercises aiming for 35% of maximum heart rate.
At the end of six months she assessed both groups.
Aerobic Exercise Reversed Mental Decline
The stretching group saw no cognitive benefits. Their brains continued to shrink, blood flow to the brain did not improve, ability to carry out day-to-day tasks continued to go downhill, and tau protein levels in the brain that are associated with Alzheimer’s showed no improvement.
The story for the aerobic group was quite different.
They had a significant increase in brain size, blood flow to the brain increased, there were improvements in their ability to plan, carry out multiple tasks and daily activities, and the level of tau protein decreased.
This was the strongest evidence to date that exercise can treat early signs of dementia.
Professor Baker also carried out a study with the same exercise protocols but with 76 patients diagnosed with Alzheimer’s. Even among these advanced dementia cases, those in the aerobic group experienced a slower rate of memory decline than did the group that merely did stretching exercises.
Among the aerobic exercisers, the hippocampus area of the brain that’s so crucial for retaining memories actually grew.
In an earlier interview Professor Baker said exercise can modulate the risk of cognitive decline in a number of ways.
“Exercise exerts benefits on inflammation, improves the integrity of both macro and micro [blood] vessels, [and] has a beneficial effect on physical and psychological stress, all of which have been shown to have potent effects on amyloid [brain plaque] burden.”
Dr. James Pickett, head of research at the Alzheimer’s Society, said, “This research suggests that it’s never too late to take up exercise.”
And to answer the question Professor Baker posed, yes we would be in a different place now if these benefits could be put in a pill. So dust off those golf clubs or tennis racket and ease yourself back into sport. Or just walk every day. It’s one of the healthiest activities there is.